New changelog entries:
* libnih1 needs a versioned Pre-Depend on libc6 instead of just a Depend,
because libc6 itself uses runlevel from the upstart package in its
preinst, which in turn uses libnih1, which needs to be loadable (i.e.,
its symbol references resolve). We therefore need to ensure that
libnih1's dependencies are always unpacked before libnih1 itself is
unpacked. While having something further up the stack (such as upstart,
or something on top of upstart) being marked Essential: yes and with the
necessary pre-depends would let apt handle this for us with its
"immediate configuration" support, but for various reasons we don't want
to make upstart essential. LP: #508083.